code: def __init__(self, in_channels, out_channels):
      super().__init__(aggr="add")
      self.lin = torch.nn.Linear(in_channels, out_channels)
  
file_path: pytorch_geometric/test/nn/conv/test_create_gnn.py
imports: import torch
  from torch_geometric.nn import MessagePassing
  from torch_geometric.utils import add_self_loops, degree
label_desc: Use image node_id 1 to create a new GCNConv object from inherited base classes: MessagePassing with example: obj = GCNConv(in_channels, out_channels)